Escapement mechanism for typewriters



Aug.. 12, w45 A o. A. HOKANSON ESCiUEEMEN'l` MECHANISM FOR TYPEWRITERS Filed May 14 1920 2 Shww-Shw?. 1

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O. A. HOKANSQN ESCAPEMENT MECHANISM FOR TYPEWRITERS Filed May 14. 1920 2 Shaw-Shcm 2 Q MMU?? 7% Patented Aug.. l2, i924.,

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ESCAPEMENT MECHBJUSM FR TYPEWTRTERS.

Application filed May 14, 1920.

TooZZ whom t may] concern.'

Be. it known-that l, Gr'ro A.. lloimNsoN, a citizen of the United States, residing at Woodstock, in the county of McHenry and State of `Illinois7 have invented `certain new and useful Improvements in Escapement Mechanism for Typewriters, of which the following is a specification.

This invention relates to escapement mechanism for controlling the movement of a typewriter platen carriage and has for its object the provision of mechanism of the class named which shall be of improved construction and operation.

The invention is exemplified lin the combination and arrangement of parts shown in the accompanying.drawing and descril'ied in the following specification, and it is more particularly pointed out -in the appended claims.

ln the drawingj F ig. 1 is a fragmentary vertical sectional view through a portion of a typewriter platen bed showing one embodiment of the present invention appliedthereto;

Fig. 2 is a horizontal section substantially on line 2 2 of Fig. 1;

Fig. 3 is a vertical section showing the escapement dog vibrator and escapement wheel as viewed from the left in Fig. 2;

Fig. i is an elevation of the escapement dog vibrator viewed from the right in Fig. 2.

Fig. 5 is a fragmentary yplan showing a portion of the mechanism illustrated in Fig. 2 but having a slightly different ad-v justment; and

Fig. 6 is a fragmentary side elevation a portion of a typewriter having the present invention applied thereto.

In the embodiment of the invention shown in the drawing, a platen carriage bed 10 is provided with V-ways 11 along which ball bearings 12 are arranged to travel. ii

platen carriage 13 is provided with 'tf-ways* 14 for engaging the ball bearings 12 by means of which the platen carriage is rap ported in position to move freely along the` .platen bed 10. A ball spacer 15 may be provided to retain the balls l2 in proper relative position to one another, and the carriage is made in two sections adjustably connected to one anotherby cap screws to facilitate assembling and to permit adjustment of the ways relative to one another to regulate the Serial No. 381,250;

bearing on the balls 12. The carriage 13 is provided with the usual spring motor for moving' it in one direction along its supporting bed and has a rack bar 16 connectedthereto to move in unison therewith. rlhe teeth of the bar 16 engage the teeth of a pinion 17 which is carried by a shaft `18 journaled in a bearing member 19 inserted in an opening in the carriage bed l0 and held in place'by having a portion thereof rive ed into the opening in the bed 10, as illustrated at 20. the opening in the bed being` counterbored to hold the bearing 19 in place after it has been riveted. The shaft 16 projects below the bed plate 10 and has an esca )ement wheel 21 secured thereto by any suitable means, such as set screws The rotation of the escapement wheel 21 is controlled by a fined dog 28' and a movable dog 24 which are carried by a rocker plate 25. `he .fixed dog 23 is integral with or rigidly secured to theplate 2, and the movablevdog 2t com prises a 'sliding bar 26 having a slot 2l" engaging a pin 2S on the rocker plate The plate 25 is provided with a tongue 29 which is bent about the sliding bar 26 to hold it in position on the plate. A spring 30 is secured to a tail-piece 31 on the bar 26 and has its opposite end attached to a pin 52 on the plate 25 so that the spring normally urges the dog n3 into position to meet one of the teeth 32 of the cscapement wheel 21.

The rocker plate 25 is provided with bearing lugs 33 which are pivotally supported by stud screws 34 threaded in ears which ei:- tend downwardly from a supporting plate 66. Loch nuts 3'? are provided for holding the stud screws 34: in position. rfhe plate 36 is carried by the lower face of the carriage bed 10 and a spring E8 is interposed between the tail-piece 39 of the plate 25 and the lower face of the plate 36, the spring 3S being held in place by a suitable recess and projection on the plates 36 and 25, respectively. The amplitude of the vibrations of .the plate 25 upon its pivot supports la is controlled by adjustable screws -l-O and al threaded through the plate and provided with loclr nuts Li2 and Lil-3, respectively. The ends of the screws 4:0 and Li1 are arranged to strike the lower face ofthe plate. 36 to limit the movement ofthe roclier plate 25.

rlhe rocker plate 25 isoscillated by a` universal lever i-lp'ivotedon a shaft fl-5 supported by ears i6 extending downwardly lltl from the bracket member 47 which is secured to the carriage bed 10 by screws 48. The lower arm 49 of the .lever 44 is provided with a tongue 50 cut in the plate which forms the arm 49 and oifset therefrom to receive a linger 5l projecting from the end of the rocker plate 25. The upper arm 52 of the lever 44 is provided with a head 53 positioned in the path of movement of the type bars as they swing into position to strike the platen 55. The bracket 47 extends upwardly to form type bar guides 56, and the and the xed dog 23 will simultaneously engage the front face of the tooth previously contacting the face of the movable dog.. As

. soon as the movable dog 24 is released from the escapement tooth 32 the dog will be drawn forwardly by the spring 30 until the .rear end of the slot 27 eno'ages the pin 28.

c As soon as the type bar 54 begins its return movement the lever arm 52 will be released and the rocker plate 25 will be swung about its pivotal supports by the spring 38 to return Vthe dogs 23 and 24 to their uppermost position. This will free the tooth 32 of theY escapement wheel 2l fromrthe liXed dog 23 and permit a partial vrotation of the escapement wheel for the reason that the dog 24 has been moved forwardly past the tooth of the escapement wheel and is no longer in position to re-engage the tooth of the escapement wheel previously in contact therewith. As the escapement wheel is rotated by a movement ofthe carriage platen the next succeeding tooth 32 will engage the face of the movable dog 24 and carry it back against Ythe tension of the spring 30 until it is stopped bythe contact between the pin 28 andthe forward end of the slot 27.

Thus,

Y Vthe carriage isfed theV required amount at each stroke of a type bar and immediately after the type has been moved away from the platen. Y

As shown in Fig. 4, the active portions of the dogs 23 and 24 have their adjacent faces cut away leaving` the portions of the dogs which contact with the teeth of the ratchet be brought into alinement with the escapement tooth before the other dog has moved out of contact with the tooth, but because the dogs are spaced apart the amoclmt of movement to shift from one dog to the other is less than would be necessary if the dogs were in direct contact.

If it is desired to operate the escapement wheel in two steps instead of one., the active dog 24 may be held iu advance of the fixed dog 23 by the slot 27 and the pin 2S, as shown in Fig. 5. With this arrangement it is apparent that when the active dog 24 is moved out of engagement with the tooth 32 by the forward stroke of the type, bar the escapement wheel will rotate until the tooth 32 strikes the fixed dog 23. Upon the return movement of the dog rocker the cscapement wheel will make the second step in its movement to complete the feeding movement of the platen. By this arrangement the movement of the platen is divided into two steps, one of which occurs just before the type strikes the platen, and the other ci' which occurs after the type has left the platen on its return movement.

It should be noted that the universal member 44 for operating the dog` rocker is connected directly with the rocker, and also is directly engaged by the type bar at a point adjacent the platen. By this arrangement there is very little chance for lost motion between the type bar and the dog rocker so that movement of the escapement mechanism can be very accurately timed with relation to the time of contact between the type and the platen7 and since it is not necessary to allow for lost motion the amount of movement of the dog rocker can be reduced to a minimum. rPhe direct connection of the universal member with the type bar and the dog rocker also permits i of the use of very few parts and simple construction and facilitates compactness ol' arrangement. It should also be noted that the universal member is operated by contact with the outer portion of the type bar at the end of its positive stroke. This relieves the keys of the necessity of moving` the escapement mechanism until the type bar has gained its maximum momentum .so that the operation of the escapement mechanism is produced chiefiy by the momentum of the type bar at the time that the momentum is the greatest. lt should be noted also that the point of attachment between the universal member and the dog rocker is at a point away from the pivotal axis of the rocker beyond the escapement dogs. By this arrangement a leverage is obtained in the dog rocker itself for moving the dogs, thus reducing the force required for this purpose.

As will be seen from the drawing the construction is such that the parts may be compactly arranged in a minimum space and yet the parts are all of the simplest conllt) struction so thatpractically all ofthe parts may be stamped yfrom sheet metal. The carriage bed and the plate-n carriage have their body portions formed of asingle web or plate arranged parallel with one another and spaced slightly apart by their cooperating ways forming a fiat rectangular structure within the interior of ywhich is arranged therack-and pinion mechanism for controlling the movement of the carriage on its bed. 'I he arrangement-of the shaft l@ extending through the bed plate not yonly brings the pinion l'T within the space between the carriage and its bed, but also makes it possible to arrange the escapement wheel 21 in a plane parallel with the bed plate so thatthe escapement `wheel itself projects only a slight distance from the lower yface of the bed plate, thus `economiaing space and making it possibile to position the rocher plate als-o `directly beneath the bed plate and parallel therewith. yl`hus the entire escapement mechanism, together with the platen carriage and its bed plate, constitutes substantially ra ynumber of fiat plates arranged one upon the other and spaced only short distances apart, thus providing a maximum economy of space and also employing parts of the simplest construction. In this connection it is noted also that the fixed dog 23 is formedby a part of the rocker plate 25 itself so thatonly one piece is necessary forzthese two elements of the mechanism.

Not only are the 'parts simplyconstructed and compactly arranged, but the entire escapement mechanism, as well as the universal member for operating themeehanism are all mounted upon the'same support so that the escapement mechanism and the operating member therefor constitute a single unit, the parts of which have a definite fixed relation to one another independent of the other parts of the typewriter. Such an arrangement is especially advantageous when combined with a folding support for the carriage bed, such as is illustrated in Fig. 6 of the drawing, in whichthe bed plate l0 is shown ycarried by arms 60 pivotally mounted at 6l on themain base frame 62. Since the universal member 52 is supported by the bracket 4:7 on the carriage bed plate and is operateddirectly by the type bars without any connection with the key levers it is possible to fold the carriage with the entire escapement mechanism thereon, without the necessity of providingany separable driving connection fto be made and broken when the carriage frame is swung into and out of'operating position.

I claim zl. In a typewriter, a platen carriage comprising1 a plate,` a bed for said carriage comprising a plate arranged substantially parallel with the plate of said carriage, said tra plates having"cooperating ways for guidingsaid carriage on said bed and for spacing said plates from one another, an escapement wheelhaving a lined plane of rotation arranged substantially parallel with said plates,` and rack and pinion mechanism positioned within the space included between said Vplates and controlled by said escapement wheel for regulating the movement of saidcarriage on said bed.

2. In atypewriter, a platen carriage bed plate, a separately formed journal bearing extending transversely of said bed plate and secured thereto, a shaft journaled in said bearing,y an escapement wheel secured to said shaft on one side of said bed plate and having the plane thereof extendingin the direction of the plane of said bed plate, a pinion carriedby said shaft onthe side of said bed plate opposite said escapement wheel, a platen carriage arranged to travel on said bedplate, and a racl secured to said carriage and meshing with said pinion.

3. In a typewriter, a platen carriage bed, a platen carriage movable along said bed, and eseapement mechanism for controlling the movement of said carriage on said bed, said Aescapement mechanism com 'sing a dog roclrer positioned closely adjacent one faceiof said carriage bed and extending in the direction of the plane thereof.

4. In a typewriter, a platen carriage bed, a platen carriage movable on said bed, escapement mechanism for controlling` the movement of said carriage on said bed, said mechanism comprising an escapement wheel arranged closely adjacent one face of said bed and having the plane thereof arranged to extend iir the direction of the plane of said bed, and a dog rocker for controlling said escapement wheel', said dog rocker being positioned closely adjacent said face and arranged to extend in the direction of the plane of said face.

5. In a typewriter, a platen carriage comprising a main sheet metal body portion, a

platen'carriage bed comprising a main sheet metal body portion, an eseapement wheel for controlling` the movement of said carriage on said bed, and a rocher plate for controlling said escapementwheel, the body portions of saidcarriage and bed, the plane of said escapement wheel and said rocker plate all being arranged to extend in substantially parallel planes.

G. In atypewi'iter, a platen carriage bed, an eseapement wheel mounted on said bed adjacent one face thereof, and a rocher plate for controllingA the movement of said escapement wheel, said Vplate being pivoted adjacent said face of said bed to swing about a pivotal axis extendingin the direction of the plane of said face.

i'. lIn a typewriter, a platen carriage, a bed for said carriage, and escapement mechpivoted to said bracketto oscillate about an axis extending parallel with said face, and means to limit the movement of said oscillating member to maintain said member in a position approximately parallel with said face. A Y

9. Escapement mechanism for a typewriter comprising a platen carriage bed plate, an escapement wheel arranged adjacent one face of said bed plate and having the plane thereof extending in a direction parallel to the Vplane of said face, dogs for controlling said escapement wheel, a rocker plate for controlling said dogs, said rocker plate being arranged adjacent said face of said bed plate and pivoted to swing upon an axis extendingin the direction of the plane of said face,-and means for limiting the movement of said rocker plat-e to maintain said plate inV a'position approximately parallel with the plane of said face.

10. The combination with a platen for a typewriter, of a carriage therefor', a bed for said carriage, escape-ment mechanism for controlling the movement of said carriage on said bed, and a universal member for operatingrsaid escapement mechanism, said member having an armextending adjacent said platen and in thel path of a type bar.

11. In a typewriter, a platen, a carriage therefor, a carriage bed on which said carriage is mounted to move, escapement mechanism mounted on said bed, a bracket secured to said bed and having type bar guides carried thereby, and a lever mounted on said bracket land having, one arm thereof connected with said escapement mechanism for 'operating said mechanism and having ancapement dog carried by said member at a point nearer the pivotal axis thereof than the point of engagement between said member andthe actuating means therefor, but on the same side of saiidaxis.

ln'a typewriter having a platen carriage frame movable away from operative position, the combination of escapement mechanism mounted on said carriage frame,

and a universal member for operating said escapement mechanism mounted on said carriage frame and movable therewith.

1li. A typewriter having a platen carriage frame, means for supporting said frame to permit movement thereof into and out of operatingl position, escapement mechanism mounted on said frame and movable therewith, and a universal member also mounted on said frame for operating said escapement mechanism and having means for engagement with the type bars of said typewriter to be actuated thereby.

15. A typewriter having a platen carriage frame supported for movement into and out of operating position, escapement mechanism carried by said frame and movable therewith, and a universal member connected with said escapement mechanism and supported by said frame for movement therewith, said universal member having` a portion thereof disposed in the path of movement of the type bars of said typewriter when said platen carriage `frame is in operating position so that said type bars will engage said portion and actuate said escapementmechanism when the typewriter is operated.

16. A typewriter having` a platen carriage frame mounted thereon for movement into and out of operating position, a platen carriage movably mounted on said frame, es apement mechanism for operating said carriage, and a universal member for actuating said escapement mechanism, said universal member being connected with said escapement mechanism for all positions of said platen carriage frame.

17. A typewriter having a'platen carriage frame mounted thereon and movable into and out of operating position, a platen carriage on said frame, escapement mechanism for operating said platen carriage, and a universal member mounted on said frame and connected with said escapement mechanism for all positions of said frame and positioned in the path of movement of the type bars of said typewriter when said frame is in operating position so that said universal member will be engaged by said type bars for actuating said escaj'iement mechanism.

18. A typewriter having a platen frame arranged thereon' for movement into and out of operating` position, a platen carriage on said frame, and mechanism for perating said carriage mounted on said frame and movable therewith into and out of operating position, said mechanism being actuated by engagement with the type bars of said typewriter.

19.111 a typewriter, a platen carriage frame having guideways thereon, a platen carriage comprising` a plate movable on said frame and having flanges forming ways at the edges thereof arranged to cooperate with the gnideways on said frame7 and means for adjusting one of said anges to adjust the Cooperating- Ways of said frame and carriage relative t0 one another;

20. In combination, a platen Carriage trarne having` guideivay thereon, and a platen carriage Comprising sections adjust ably connected te one another, each seetion being provided with a guideway arrange-d to cooperate with one of the Ways on said frame and adjustable With said section to permit assembling ot said carriage on said traine and the adjustment of said -Ways relative to one another.

2l. A platen Carriage frame having guides thereon provided With Ways on the outer' faces thereof7 a platen carriage having guides thereon ar anged to stride the guides on said frame and having Ways arranged t0 cooperatewith the Ways on said trarne, the guides on said Carriage being adjustable toward and from one another to facilitate ont assembling of said Carriage on said frame and to permit adjustment of said guideways relative to one another.

ln testimony whereof have signed my naine to this speeilieation on this 10th day of May, A. D. 1920.

OTTO A. HOKANSN. 

